The broad long term goal of this research is to reduce or eliminate the blindness in AIDS patients caused by CMV retinitis, the principal cause of blindness in AIDS. We have developed a sustained release intravitreal delivery system delivering 1ug/hr of ganciclovir over approximately 8 months which has recently completed phase III testing. FDA approval is anticipated in 1995. The aim of this study is to modify this system to allow development of a longer lasting device which can be implanted through a smaller incision. The median lifespan of patients with CMV retinitis is currently 12 to 18 months. Thus a device which released for 18 months would have obvious clinical advantage. The specific aims of this phase 1 project are: 1. To construct devices to deliver ganciclovir at 1ug per hour which will last approximately 18 months. 2. To test in vitro release rates for the devices in buffer and in serum. We have an agreement with a large pharmaceutical company to produce and market the current 8-month CMV retinitis implant. We would foresee continued corporate cooperation in the production and distribution of the proposed implants should this research prove successful. PROPOSED COMMERCIAL APPLICATION: CMV retinitis is the leading cause of blindness in patients with Aids. The existing implant which we have developed promises to become the treatment of choice. This work will lead to a longer lasting device which will both improve long term visual outcome and decrease the cost of care.